I am working on my portable 3d printer again, is it still worth it?

Many years ago I have made a couple of attempts at designing a portable folding 3d printer (Project Create and Project Resha). Back then I had very little money and time due to my studies, which prevented any meaningful progress. Now I have slightly more time, so I decided to revisit the latter design, though progress is still too slow.

I had thought that by now someone would have built a commercial printer like that, but none did. I thought maybe no one really cares for portability, but then Ultimaker made the Go, and nearly everyone I spoke to in person said it's a fantastic idea (after actually seeing the prototype). On the contrary, most people I spoke to online think its a bad idea, especially for a product.

So I am asking you, do you think its a good or a bad idea? Some details are here: https://goo.gl/forms/b1c0M5JIlPZJbBEx1 . I would also love it if you fill the top three questions on the form.

The stepZero looks interesting for a small laser engraver or such. Does it have spare PWM pins?
I've tried to make use of the PiZero, but it always ended in a mess of cables and adapters. It seems you've sorted that out and even have micro-USB WLAN support?

I haven't yet thought about a portable printer. Who's driving around with a printer in his backpack? If I want to join conventions or exhibitions, a huge but foldable printer makes sense. But I can't find an "excuse" to have one in my shop. They are busy 24/7 anyway, so no need to store them neatly. My major interest is reliablity.

To make money? unlikely, you can not compete with china's mass production of cheap 3d printers (some of them are even ok). Also if it should turn out to be popular they will just clone your design and under cut your prices...

If you want a portable printer because you really want a portable printer. Go for it

Yes, there are a couple of PWM pins, but that depends on how many end-stops do you plan to have.

Because I didn't have any space on the left side of the board (I needed at least two expansion ports, one for extruder and one for bed), I broke out the two PWM pins on the connectors that are originally intended for the x-axis end-stops (see here stepZeroR2 pins). If you only want one home end-stop per axis, then you can connect the x-axis end-stop to the spare y-max and use the x-min and x-max as PWM.

I have used a micro USB WLAN dongle on the regular RPi Zero at first, but I would recommend using the RPi Zero W if you want WiFi. Not only for saving space, it's more reliable, very close in terms of cost, and you get to keep the only USB port free for something else.

I am interested in your idea about the laser engraver, are you planning on building one?

My printer design is certainly not suitable for a shop or a workshop. It's useful for individuals who have little space, move a lot, or go to events or temporary workplaces with their printers. This could be for example people who provide 3d printing training (that's the only example on Ultimaker Go page).

I definitely will continue to make and improve one for myself, I actually need one at the moment as I had to give away my regular-size desktop printers due to moving to a city centre flat, so no space for hobbies.

But I also wanted to make some money. Yes, I totally get your point, it's hard to compete on price with Chinese mass production. But as you said "some of them are ok", there is definitely a market for quality. If I would allow myself to be discouraged by the prospects of Chinese copies then I guess there's no point in any attempt to make anything new.

I think that if you need a portable printer that folds up, it's a great project that you should continue to work on. Projects like that are always worth doing for the experience, and you may develop something for it that can become more widely useful, even in non-portable printers, or even in other types of machines. I don't think it's a trivial task to design a high precision mechanism that can fold and unfold and maintain print quality. There are a lot of interesting problems to solve there.

However, I also don't think the market is clamoring for a foldable printer. The only thing I see the market clamoring for is a cheaper printer. Very few people care enough about high quality machines or prints to pay the cost of achieving either. It's hard to imagine a market where people are willing to pay for a folding mechanism. The mass market for 3D printers is a "good-enough/cheap enough" market. Your folding printer seems like more of a personal interest project to me. But what do I know?

I have a bit of a soft spot for portable machines since I went to an out of province university and currently live in an apartment. My most complete attempt at a portable device was a cnc router: [hackaday.com]
It suffered from rigidity problems (too much Z-travel + unsupported rail) which more or less constrained it to plastic, however it saw considerable use at school and even travelled it through airport security multiple times.

Traditional machine design is already quite challenging, but a well designed portable device must also consider weight, compactness, wire management, repeatable unfolding (preferably without tools), and be very robust. If you build a printer for travel expect it to take abuse. The Printrbot Go was a commercial portable printer, but the design was pretty clowney (to be polite) and I'm not surprised it never gained traction.

Although 3d printers seem more suited to portable designs, I had trouble fitting one into a matching briefcase because I really wanted to include filament and a permanently connected bowden within the case as well. There are already plenty of printers small enough to toss into a backpack so if your portable design requires set up and spools of filament there isn't much point.

either single Z or dual, ideally just one but it would be a sturdy little beast with 2,
or make something a little cheaper,
so vertical Z bar £20 with linear rail (or just utilize the dovetail), H bar another £20(same again), then maybe belt or an expanding Y.
One that Moved in XYZ and printed on the Table would be cool.

First of all that's an awesome build, I hope it's still alive and kicking.

As for my design, I am aware of such requirements. I was originally designing mine with steel inner structure and carbon fiber housing and using relatively expensive components, unfortunately at the moment that would also mean higher price, which is currently the biggest challenge that I need to work on if this is to ever be a product. I want to make it so as to require minimal set up, such as unfolding the bed without tools. I am also hoping to make a compact filament spool that fits inside it.

Anyways, regardless of it's commercial potential, I'll keep working on it and publish my progress. I hope you like it when its done.

John, I am afraid I'm having hard time imagining what you're describing. As for printing on the table, that would be cool indeed. You'd most probably still need some print surface on the table for the filament to stick to it though.

The way Printrbot does its X axis could be done with the sliding focus plate ie hotend on the end of plate, join it to another for the Z with the circular thing and Z could rotate. Y similar but not printing on table at the moment. Y would need to be attached to base of Z to have the thing move in all 3 axis, possibly an alternate part or 2 to make it work. ie a normal plate with something like this

the StepZero is looking very cool, i`m also searching for a small electronics for my tiny printers since years.

As the board only has 3 Stepper-driver connectors will the Extruder stepper then be driven by this daugtherboard ?
have you considered using a AT90USB1286 instead of the 1284, afaik i noticed when testing boards the bottleneck is not the speed (thats why you clock the 1284 at 20mhz?) but the slow serial interface.

the StepZero is looking very cool, i`m also searching for a small electronics for my tiny printers since years.

As the board only has 3 Stepper-driver connectors will the Extruder stepper then be driven by this daugtherboard ?
have you considered using a AT90USB1286 instead of the 1284, afaik i noticed when testing boards the bottleneck is not the speed (thats why you clock the 1284 at 20mhz?) but the slow serial interface.

Chri

It's no so much the speed of the serial link, it's the fact that it has no flow control so the PC or Pi has to keep waiting for "OK" responses from the 3D printer controller. Microcontrollers with native USB support avoid this.

But why are people still designing/proposing boards built around obsolete high pin count 8-bit microcontrollers, when modern 32-bit ones are so much more capable and half the price? For example (prices from digikey.com):

Not everyone does need a high-end Board with lots of "bling bling" on it.
Not everyone does want or can afford such high-end boards like DUET /WIFI
Not everyone does need/wand such huge boards where you can eat lunch on.
Not everyone does have the skill to work on new generation technology or does have the possibility to manufature those in small quantities.
There are still people who want or need a small and more important, affordable board that just do the basic stuff.

Also comparing the cost of the chip is useless, what counts is the cost of a complete board, and this is where your DUET board is WAY too expensive for most cases.

I just checked the cost for your board at a companys here at Germany for example, the board already costs 190 € , the smallest Display does cost 100€ so basicly with shipping you have to pay at least 300 € to get delivered an electronics with a Display.
The cheap chinese $40 € boards beside, normally also good quality Ramps Kits with displays don`t cost more than 100€ to 130 €.

To take it in comparison for example with Intel CPU`s, for sure a Intel i9-7000 is very fast, will often be awarded and makes good publicity.
But what People do buy are the Midranged I5 and I7 CPU`s, thats where the sales go, your Board is a I9-7000 Extrem with all that is possible at the moment, buts its expensive and has too much cores even most high end games can not use all power, and is not sold alot.

Ultimaker is using a normal 8 Bit board for printing on their Ultimaker 3 and have an additional 32bit board for the fancy stuff.
So for printing a 8 Bit board still has enough power to do its job on a cartesian printer.

Chri, you've missed my point entirely. If you want to make a cheap 3D printer board, you should not choose an expensive obsolescent 8 bit processor, you should choose a modern ARM processor that costs less than half as much - and makes the firmware easier to write because you are not constantly trying to make do with limited RAM. Nothing to do with what functionality you choose to provide.

As you already written the cost of both chips, 3€or 6€ that is a really tiny difference in cost so this is not really a big factor when it comes to an overall cost of 100 € or 300 €, thats a real difference.

When it comes to cost using something based on a existing firmware (and an existing HW design) is always the cheapest way, not only using the cheapest chip.
i know that a 32 Bit CPU is "better" and cheaper, but thats not all that counts.

Considering a Board design has more (cost factor) components than only CPU cost and Firmware writing

* what is the cost of the CPU
* how much of additional components are needed with different CPU`s
* what is the cost of the additional parts
* how complex is a board design compared to different cpu`s ( 2 / 4 layer, board size)
* what level of Manufacturing is necessary (no SMD, only small ammount of SMD, all SMD )
* What firmware will be used -> which programming knowledge is available
* has the complete manufaturing process to be done by an external company, or can something be made "inhouse" , what can the customer do by himself.
* has new code to be added to the firmware or has only existing code to be changed (thats a big deal for amateurs where not all of them have knowledge in all programming languages)
* Which features are really necessary, which features are only a "nice to have"
* Fixed or Plugable Stepperdrivers, this is a essential cost factor as alot people have already drivers, so for them the overall cost of upgrading is lower.
* ect...

In my early 3D days i bought a couple of Sanguino`s from T3P3 , and you know why ?

Because it was cheap, cost was about 120 € with display in that days.
Because it had all the things that i needed.
Because i was able to build it by my self, which safed me money and on top i learned a little bit more about the electronics in detail.
Because i was able to fix the board by my self then a part blow up when i overloaded the hotbed output.
Because i was able to upgrade my old 664 CPU to a 1284 for low cost , and not had to buy a new board.
Because i was able to be able to use different stepper drivers, depending on my requirements i had.
Because i was able to buy an affordable Display that has all the Basic stuff i needed, i even designed a enclosure for that.

For me it seems that you still don`t understand that there are people with different demands in this world and all this design factors have to be considered, not only the cost of the CPU and if a software can be written easily or not.

Chri, you persist in assuming that I am only interested in Duets and I don't recognise that other market segments have different needs. Get over your preconceptions and read what I write.

The sam4s processor I compared with the at90usb1280 is not the one used in the Duets, it's what I would use if I were designing a low cost board now (or perhaps an ESP32 instead). It would be very easy to port RepRapFirmware to the sam4s. It can be used with a 2-layer PCB (I use a slightly older version of that chip on a 2-layer board). And if you are designing a low cost board that is intended to be mass produced, a $3.60 difference in price is very significant - and the price differential is likely to widen.

If you want to make a board yourself using no SMD parts at all, that's a whole different ball game, and even in 8-bit processors it leaves you with very little choice.

I assume you are primary only interessted in a "all featured" board, thats what came to my conclusion with all the other threads we discussed about that, that there only exists the DUET it only the proove of it.
And i assume that you not have really thought about the components i listed before...

should mbhassan answer why he choose the 8 Bit, maybe then wou will also know ...

the sanguino was an example from the past time, for sure i know that a board with no SMD components at all is a very limiting thing nowadays, when you remember my other threads i was also for more SMD parts, not less.
for sure i would use a 32 Bit electronics before a 8 bit, but there does not exist on with the demands i need, his 8 Bit electronis is more promising to meet my demands than any other 32 Bit UFO available at the moment.

I think hardware development at the low end of the 3D printer controller market has got stuck in a rut, because there is no money to be made from making low-cost 3D printer electronics. I started on a low cost design using an ARM Cortex M3 processor 2+ years ago before I got involved with the new Duet designs. As a concession to the market, it had plug-in drivers even though they are technically a bad solution, but with an option of using an extra pin on the drivers to allow firmware control of the current. I stopped work on that design when I realised that allowing for enough margin to provide distributor discounts and a reasonable warranty returns policy, the retail price would have to be about £60+VAT if it was assembled in the UK; and you could already get a Smoothieboard rip-off or a Replikeo Duet 0.6 for less than that.

You can find the incomplete design at [github.com] if you are interested. I'd change a few things if I was doing it again - for example, ARM Cortex M4 processors now cost less than ARM Cortex M3, and adding WiFi is cheap to do - but not much.

We've also looked at doing a low-cost version of the Duet WiFi, with cheaper driver chips, less features and less expansion capacity. But again, the margins make it difficult for a Western company that wants to keep a reputation for good support and a good returns policy to manufacture and sell at a profit. It might work for a company that isn't so concerned about reputation and already has good links to a manufacturing company in China.

I wanted something tiny to drive the steppers and fits under the stepstick drivers, I don't need any other features, and I use Marlin which wasn't officially supported on 32bit boards at the time. Also, I don't need or use a high pin count 8-bit mcu (atmega1284p has less pins that Arduino Mega atmega2560) and it doesn't cost twice as much as the ATSAM4S4BA-AU. I admit the geeky part of my wants 32bit mcu, but it also wants a 4k screen on a phone that I only use to read stuff. The atemga1284p and Marlin does what I need and I can prototype it myself (I know ATSAM4S4BA-AU comes in small packages, I can't solder BGAs myself, I'll be looking into this chip for future boards though).

Chri:

I am glad you like stepZero. Your search is over :-)

I don't understand the benefits of using the AT90USB1286, is it the USB interface? I wouldn't use that as the board is intended to work with a RPi Zero via the RPi UART. Also the AT90USB1286 costs twice as much as the ATmega1284p and the package is larger so won't fit between the headers for the StepSticks.

Yes, the daughter board is meant to drive the extruder. That's indeed partially the reason for the 20MHz. The original idea was to control the extruder entirely via UART or I2C, which won't work. So right now the daughter board is driven by four signal wires, two for UART or I2C, the other two are intended to be used as a multiplexed pins to directly pulse the stepper or read a limit switch. The UART or I2C is used to set and poll the nozzle temperature and select the mode for the other two pins.

Yes its legitimate to say that the risk for you personally is to high to be successful in this market sector and if you don`t want to invest okay, we have to deal with it ^^
But only sayin 8 bit is sh*t because it`s old and new stuff is available it not a solid answer, there always have to be considered more things.

It`s my opinion that there is still room for a board that has the potential to be the new ramps board.
60 Punds +vat does not sound expensive to me for a board with just the right featureset a great open source firmware (what Reprapfirmware seems to be) there is still room for a 32 Bit board.
Combined with a simple black and white display the deal should be doable.

@ Mo,

I did very high speed tests (print speed 400mm/s Acc 9000 and yerk 50) long time ago and noticed that i got heavy stuttering when printing via the Serial connection.
this issues were much less when printing from SD card, so for my thought the serial connection was too slow to deliver the informations fast enough.
I have a AT90USB board but i never had time to test the board with a AT90USB chip on this printer.
But as already connecting to a AT90USB does only take about an half second, while connecting to the 1284p takes over 10 seconds.
A a second benefit on normal boards is that you don`t need an additional RS232 to usb converter chip, where i think the bottleneck is.
but as the Pizero has only one USB, it seems to be better to go in to them directly via other pins, and the Stuttering does only come up on higher speeds.

I don`t know if your board design is already completely finished or if you still may consider to make changes, if so, maybe doing some of the pins with 1,27RM connectors will give you more space to add a Pinrow to be able to connect the 4th stepper directly to the chip ?